Lining tunnel wall made by shield type tunnel excavator

Abstract

A tunnel wall lining method is provided, wherein annular recesses circumferentially are provided in outer periphery of a lining form into which arcuate segments are assembled, a plurality of rows of reinforcing bars are arranged annularly in the respective recesses of the lining form, and a lining is constructed with concrete cast into a space between the tunnel wall and the lining form. The lining thus constructed includes circumferentially extending and radially inwardly projecting beams in which the reinforcing bars are embedded, whereby a lining having a reinforcing structure can be constructed in a simple and economical manner and in a shortened construction period.

What is claimed as our invention is: 
     
       1. A method of lining a periperhal tunnel wall made behind a shield type tunnel excavator as said excavator is advanced, the method comprising the steps of assembling a plurality of arcuate segments into an annular lining form, each segment having an arcuate recess for forming annular grooves in the outer periphery of the lining form when said segments are assembled, providing in said annular grooves a plurality of reinforcing bars, disposing said outer periphery having said annular grooves of said lining form to oppose said peripheral tunnel wall, and casting a lining material into a space defined between said peripheral tunnel wall and said outer periphery of the lining form to construct in said space a lining having annular beams circumferentially extending and projecting radially inwardly, said beams having said reinforcing bars embedded therein and acting as reinforcing structure. 
     
     
       2. A method according to claim 1 wherein said lining having said annular beams is constructed as a primary lining and whenin the method further comprises a step of making a secondary lining on said primary lining by casting said lining material at least into annular recesses defined between said annular beams. 
     
     
       3. A method according to claim 2 wherein said step of making said secondary lining includes convering the inner periphery of said annular beams with said lining material. 
     
     
       4. A method according to claim 2, wherein said arcuate segments are substantially M-shaped in section and have means for casting said lining material radially outward into said grooves, wherein said segment assembling step comprises further steps of positioning said lining form to overlap with a tail section of said shield type tunnel excavator and fitting a shiftable end frame between said tail section and said lining form, and wherein said lining-material casting step for constructing said primary lining comprises further steps of casting through said radially outward casting means of the segments the lining material into said annular grooves of the lining form with said end frame fitted in a position to close the grooves, shifting the end frame from said position of closing the grooves following said advance of said excavator, and casting the lining material into a space defined between said peripheral tunnel wall and said lining form. 
     
     
       5. A method according to claim 4 wherein providing said reinforcing bars includes arranging circumferential arcuate bars in top and bottom parts of the respective grooves and linking said top and bottom arcuate bars with connecting bars in a direction transverse to the arcuate bars to form a cage. 
     
     
       6. A method according to claim 5 further comprising, prior to said step of making said secondary lining, a step of exposing both ends of said connecting bars embedded in said beams and extending the ends parallel to the tunnel wall. 
     
     
       7. A method according to claim 6 wherein said step of making said secondary lining includes further steps of providing a plurality of arcuate reinforcing bars linked to said exposed ends of said connecting bars in said annular recesses defined between adjacent beams, disposing against said annular recess a further lining form for forming said secondary lining, said further lining form comprising segments having means for casing said lining material radially outward into said annular recesses, and casting said lining material into the annular recesses through said casting means. 
     
     
       8. A method according to claim 7 wherein said reinforcing bars provided in said annular recesses between said annular beams of said primary lining include further connecting bars linked to said exposed ends of said connecting bars embedded in the beams and further arcuate bars linked to said further connecting bars to form circumferentially extending annular cage. 
     
     
       9. A method according to claim 1 wherein providing a plurality of annular reinforcing bars includes providing said bars while assembling said arcuate segments into said lining form. 
     
     
       10. A method according to claim 9, wherin providing said annular reinforcing bars while assembling said arcuate segments includes joining arcuate segments of reinforcing bars respectively disposed in said arcuate recess of each arcuate segment.